package com.iron.gateway.handler;

import lombok.extern.slf4j.Slf4j;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.HandlerFunction;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.reactive.function.server.ServerResponse;
import reactor.core.publisher.Mono;

import java.util.Optional;

import static org.springframework.cloud.gateway.support.ServerWebExchangeUtils.GATEWAY_ORIGINAL_REQUEST_URL_ATTR;

/**
 * Hystrix 降级处理
 *
 * @author YT
 * @date 2019-07-10
 */
@Slf4j
@Component
public class HystrixFallbackHandler implements HandlerFunction<ServerResponse> {

    @Override
    public Mono<ServerResponse> handle(ServerRequest serverRequest) {
        Optional<Object> optionalUris = serverRequest.attribute(GATEWAY_ORIGINAL_REQUEST_URL_ATTR);
        optionalUris.ifPresent(optionalUri -> log.error("网关执行请求:{} 失败 , Hystrix 服务降级处理", optionalUri));
        return ServerResponse.status(HttpStatus.INTERNAL_SERVER_ERROR.value())
                .contentType(MediaType.APPLICATION_JSON)
                .body(BodyInserters.fromValue("{\"code\":500,\"msg\":\"Internal Server Error\"}"));
    }
}
